Besides having the missing file issue certain objects were not updating with newly saved exported datasmith file such as outlets and sconces that were adjusted, so I thought about how I separated the exported revit datasmith files. It does make sense that if something is attached to something else that it may not update due to the relationship.
I also wondered if AI would be able to help out with the missing file issue, so I asked AI about my Revit to Twinmotion issues: these are the steps I now take and have yet to have these issues stated above since.
I export all items that are attached to each other such as wall hosted outlets and sconces, and they now update.
Asking AI these questions: A. should I keep my Twinmotion project on the server, or on my local PC and sync to the server? AI answer was to keep on local PC. B. Should I open the recent projects online Twinmotion, or open them in their location on PC? AI answer was to open them on my local PC, so the cache gets deleted and reconnects project with new cache.
Ever since I have been doing this, I have not had any missing files nor objects not updating.
General: Datasmith exports over the Revit live sync file has been a faster way to work, as far as being able to export levels that may take a little time to get right only to save time in Twinmotion.
Ok, hope this helps for anyone else who may have confronted these issues.